The present invention relates generally to seat belt webbing retractors for vehicles, wherein it is desirable to have the belt storage reel freely rotatable to allow routine belt adjustment by a passenger. However, it is mandatory that during a crash or other emergency the retractor lock to prevent continued protraction of the belt.
Retractors have incorporated means for sensing changes in vehicle momentum or attitude. These retractors lock the belt storage reel when the vehicle undergoes changes in momentum above a predetermined limit or where it flips or rolls over.
In the prior art the inertia sensing mechanisms have had a direct load-bearing function during lock-up. An example of such mechanism may be found in United States Pat. No. 3758044 (Nilsson) Sept. 11, 1973.
In addition, separate housings within the retractor frame have been required to contain and protect the inertia sensing mechanism.
One of the objects of the present invention is to provide an improved inertia sensing safety belt storage reel lock actuating assembly which bears no load during an emergency. The load being transferred directly from the belt to the retractor frame and not through the inertia sensing mechanism, will allow the use of low-cost plastic parts within the inertia sensing mechanism.
A further object of the present invention is to provide a self-contained inertia sensing mechanism which will obviate the need for a separate housing for the inertia sensor and result in a smaller over-all retractor size.